1. Field of Invention
The present invention relates to a pixel circuit, and more particularly relates to an AMOLED compensation pixel circuit with improved IR drop.
2. Description of Related Art
FIG. 1 shows an organic light emitting diode pixel circuit of the prior art. The pixel circuit is a voltage type pixel circuit. The pixel circuit has a light emitting diode 110, a driving transistor 130, a capacitor 150, and a first switch 170. The light emitting diode 110 has a first end 112 receiving a first supply voltage 120. The driving transistor 130 has a source 132 and a drain 136 respectively receiving a second supply voltage 140 and coupled to a second end 116 of the light emitting diode 110 through the first switch 170. The capacitor 150 has a first end 151 coupled to a gate 134 of the driving transistor 130 and a second end 152 receiving the second supply voltage 140. The first switch 170 is controlled by a first scan signal (SN1) to couple the drain 136 of the driving transistor 130 to the second end 116 of the light emitting diode 110.
The pixel circuit has a second switch 180 controlled by a second scan signal (SN2) to couple a data line 185 to the pixel circuit through a transistor 187.
The transistor 190 is controlled by the first scan signal from the neighbor data line (SN1-1). The transistors 187 and 190 are arranged to compensate the driving voltage when the pixel circuit operates.
The drawback of the conventional pixel circuit is that it has an IR drop issue. Especially when the panel display gets bigger, the IR drop issue gets worse.